A spinneret assembly for segmented pie-shaped composite fibers

Abstract

The utility model belongs to the technical field of chemical fiber manufacturing, specifically discloses a jet plate assembly of orange petal type composite fiber. The jet plate assembly includes first, second, third distribution plate and jet plate that are overlapped in turn, the third distribution plate lower surface is equipped with boss, has opened the small hole and small groove that two kinds of melt runner are respectively communicated and are alternately spaced arrangement on the boss. When preparing, two kinds of polymer melt are distributed step by step after each distribution plate, and are prearranged into the form of spaced parallel through the boss structure, then are extruded in the jet orifice, and the orange petal type composite fiber is prepared after cooling solidification. The utility model sets up melt prearrangement structure on the upstream of final composite point, realizes the accurate control to the interface form of two components, can stably spin out the orange petal type fiber of section rule, interface clear, and lays the foundation for the subsequent efficient, uniform production of high-quality superfine fiber.

Description

Technical Field

[0001] This utility model belongs to the field of chemical fiber manufacturing technology, specifically relating to a special spinneret assembly for producing orange-petal type (also known as split type, spaced parallel type) composite fibers of ultrafine fibers. Background Technology

[0002] Orange-segment type composite fibers are an important type of bicomponent composite fibers. Their characteristic feature is that on the cross-section of a single fiber, two incompatible polymer components are arranged alternately like orange segments. This unique structural design is not intended to form a single, integrated filament, but rather to separate the two components along their interface through subsequent fiber-opening processes such as hydroentangling and alkali reduction, thereby obtaining ultrafine fiber bundles with extremely fine fineness (down to 0.5 dtex and below) and a large specific surface area. Nonwoven materials made from these ultrafine fibers possess an extremely soft hand feel, excellent water absorption, high filtration efficiency, and good mechanical properties, and are therefore widely used in high-end applications such as high-grade wiping cloths, synthetic leather base fabrics, high-performance filter materials, and lithium battery separators.

[0003] Composite spinning is the core technology for achieving mass production of orange-petal-shaped fibers. Its key lies in using a precision spinneret assembly to separately transport and distribute two different polymer melts (such as polyester PET and polyamide PA6), ultimately extruding them in a pre-set, stable, parallel configuration at the spinneret outlet. The structural design of the spinneret assembly directly determines the interface morphology, uniformity, and stability of the melt composite, and is a decisive factor affecting whether the final fiber cross-section can be regularly shaped and whether subsequent fiber opening can be efficient.

[0004] To prepare orange-petal-shaped composite fibers, the industry has proposed various spinneret assembly designs. These designs primarily focus on addressing the distribution and composite of the two melts.

[0005] A common design approach is to employ a multi-layer distribution plate structure. For example, some existing technologies disclose composite spinning assemblies comprising a feed plate, multiple distribution plates, and a spinneret. By setting annular grooves, strip distribution grooves, and through holes on different plates, the two groups of melts, A and B, are distributed from the center outwards or at different radii, ultimately guiding them to the spinneret orifice. Another more targeted approach is specifically designed for preparing petal-shaped cross-section fibers. Its components include a distribution plate and a spinneret. By setting shaping holes and channels on the distribution plate, the two components are formed into a designed petal shape on the cross-section and come into contact with each other.

[0006] Furthermore, the latest technological developments focus on the precise control of composite interfaces. For example, one utility model proposes inserting an extremely thin component separator plate into the spinneret orifice, dividing the flow channel space within the orifice into two non-communicating parts. This directly controls the interfacial morphology of the two components before extrusion, thereby producing parallel composite fibers with different interfacial structures. This reflects the current technological trend towards more precise and proactive interface control.

[0007] Although existing technologies can achieve basic production of orange-petal-shaped fibers, several technical problems still need to be solved in order to meet the demand for large-scale industrial production of high-quality, highly uniform microfibers. These problems all point to the "final stage" control of melt flow and compounding inside the spinneret assembly:

[0008] 1. Insufficient pre-control of interface morphology, resulting in uneven fiber opening: Many multilayer distribution schemes rely on "delivering" the melt to the spinneret, but the control over the microscopic arrangement of the two melts at the moment of arrival at the spinneret is not precise enough. The lack of effective "pre-forming" guidance before final compounding leads to an unstable interface state at the spinneret inlet, resulting in poor consistency in the size and shape of the orange-petal-like segments in the spun fiber cross-section. This directly affects the effectiveness of subsequent fiber opening processes, potentially leading to incomplete fiber opening or uneven thickness of the ultrafine fiber bundles, thus failing to guarantee the stability of the final product's performance.

[0009] 2. Complex flow channel design, prone to flow interference and stagnation: While complex multi-layered distribution channels can achieve broad melt distribution, the longer flow paths and frequent direction changes may increase melt resistance and create localized flow dead zones. For two melts with different viscosities and rheological properties (such as PET and PA6), this design may amplify the flow imbalance, leading to significant differences in fiber fineness extruded from different spinnerets. Simultaneously, localized stagnation within the flow channel may cause polymer thermal degradation, affecting fiber quality.

[0010] 3. Challenges in Component Versatility and Stability: Some designs using fixed separators or specific shaped holes, while achieving specific interfaces, often offer limited flexibility for adjustments based on fixed components or a specific number of segments. Changing raw materials or adjusting segment morphology may necessitate replacing the entire critical component, increasing production costs and process debugging complexity.

[0011] In summary, current technologies have not yet perfectly solved the key problem of how to accurately position, stably arrange, and pre-form the interface of two polymer melts before final lamination in a relatively simple and efficient spinneret assembly. This hinders further improvements in the cross-sectional uniformity, fiber opening efficiency, and production stability of orange-petal-shaped composite fibers.

[0012] Therefore, the technical problem of this utility model is to provide a novel method for preparing orange-petal-shaped composite fibers and a spinneret assembly to overcome the above-mentioned defects. This assembly should ensure that the two melts are precisely allocated and arranged in a preset interval parallel configuration at a critical position before entering the final spinneret orifice, thereby directly and stably spinning orange-petal-shaped composite fibers with regular cross-sections and clear interfaces, laying the foundation for the subsequent efficient and uniform production of microfibers.

[0013] It should be noted that the information disclosed in this background section is intended only to enhance the understanding of the overall background technology of this utility model, and should not be regarded as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0014] To address the shortcomings of existing orange-petal-shaped composite fiber spinneret assemblies described in the background art regarding precise pre-control of the melt interface, flow uniformity, and structural simplicity, this invention aims to provide a novel orange-petal-shaped composite fiber spinneret assembly. The primary objective of this invention is to design a core structure with melt pre-arrangement functionality, ensuring that the two polymer melts are precisely distributed and fixed in a preset, spaced-apart configuration before entering the final spinneret orifice, thereby directly spinning orange-petal-shaped composite fibers with regular cross-sections and clear interfaces. A further objective of this invention is to optimize the melt distribution path, improving the uniformity and stability of the output from each spinneret orifice, making it suitable for the large-scale production of high-quality microfibers.

[0015] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0016] An orange-petal-shaped composite fiber spinneret assembly includes a first distribution plate, a second distribution plate, a third distribution plate, and a spinneret that are stacked and fluidly connected from top to bottom;

[0017] The first distribution plate is provided with a first annular flow channel and a second annular flow channel that are isolated from each other, for receiving and distributing the first melt and the second melt respectively; the first annular flow channel and the second annular flow channel are respectively provided with a plurality of first through holes and second through holes penetrating the first distribution plate.

[0018] The upper surface of the second distribution plate is provided with a plurality of first guide grooves and second guide grooves corresponding to the positions of the first through hole and the second through hole, and the lower surface is provided with a plurality of third through holes and fourth through holes that communicate with the first guide grooves and the second guide grooves and guide the melt downward.

[0019] The upper surface of the third distribution plate is provided with at least one ring of first annular material groove and at least one ring of second annular material groove, which are spaced apart from each other, corresponding to the positions of the third through hole and the fourth through hole; the lower surface of the third distribution plate is provided with a downward protruding boss, and the boss is provided with a plurality of discharge holes communicating with the second annular material groove and a plurality of material passage grooves communicating with the first annular material groove, wherein the discharge holes and material passage grooves are arranged alternately at intervals on the lower end face of the boss.

[0020] The spinneret is provided with spinneret holes, and the lower end of the boss extends into the upper part of the spinneret holes, so that the second melt and the first melt from the discharge hole and the feed trough merge and are extruded in the spinneret holes in a spaced-apart parallel form.

[0021] The core concept of this utility model is to set up a "pre-forming station" with a precise microstructure upstream of the final composite point (spinneret) to force the final morphological arrangement of the two melts.

[0022] The component comprises a first distribution plate, a second distribution plate, a third distribution plate, and a spinneret, which are stacked and fluidly connected from top to bottom. The first distribution plate has first and second annular flow channels that are isolated from each other, used to receive and initially distribute the two types of melt in a circular pattern. The second distribution plate, through radial strip-shaped first and second guide grooves on its surface and through holes at its bottom, transforms the circumferentially distributed melt into multiple streams pointing to different radial positions. The third distribution plate is the key innovation; its upper surface receives these streams and has at least one ring of first annular troughs and at least one ring of second annular troughs spaced apart from each other; its lower surface has a downwardly protruding boss, which has multiple material passages communicating with the first annular troughs and multiple discharge holes communicating with the second annular troughs. Crucially, these discharge holes and material passages are arranged alternately at intervals on the lower end face of the boss. The spinneret is provided with spinneret holes, and the lower end of the boss extends into the upper part of the spinneret holes, so that the two pre-arranged melts can be directly merged and extruded in the spinneret holes in a preset interval.

[0023] Furthermore, the first and second annular channels on the first distribution plate are concentric annular grooves, and the diameter of the second annular channel is larger than that of the first annular channel. This structure facilitates natural and uniform circumferential distribution by utilizing the melt's own gravity and pressure, simplifies channel design, reduces dead zones and pressure unevenness caused by channel complexity, and lays a solid foundation for subsequent uniform distribution.

[0024] Furthermore, the first and second guide channels on the second distribution plate are radially extending strip-shaped channels, and the length of the first guide channel is greater than the length of the second guide channel. This design precisely matches the annular channels of different diameters on the first distribution plate, realizing efficient and undisturbed flow transfer of the melt from the annular space to a specific radial position, ensuring that the two melt streams are both spatially isolated and precisely positioned.

[0025] Furthermore, the third distribution plate is provided with N+1 rings of first annular material grooves and N rings of second annular material grooves, with the second annular material grooves located between two rings of first annular material grooves, where N≥1, and all annular material grooves are concentrically distributed radially along the third distribution plate. This "ABA" sandwich radial layout allows for a more balanced distribution of the two components in the final orange-petal-shaped fiber cross-section, resulting in a more stable mechanical structure and facilitating the subsequent fiber opening process to obtain ultrafine fiber bundles with more uniform thickness.

[0026] Furthermore, the feed channel is a groove formed on the side of the boss and extending to its lower end face, and the discharge hole is a vertical micro-hole penetrating the boss. The groove is easy to process, and the flow cross-section can be flexibly designed to adjust the flow rate; the vertical micro-hole can stabilize the melt flow direction. The combination of the two achieves the precise positioning and arrangement of the melt on a two-dimensional plane with the simplest mechanical structure, which is the core carrier of the "pre-forming" function.

[0027] Furthermore, the number of discharge holes and feed channels is 4-12, and they are evenly and alternately arranged. This range ensures that the number of segments formed is moderate, which can effectively reduce the fineness of individual microfibers, while avoiding the problems of low interfacial strength and increased spinning breakage rate caused by too many segments. The uniform arrangement is a direct guarantee for obtaining a regular and symmetrical fiber cross-section.

[0028] Furthermore, the upper part of the spinneret is designed as a conical or cylindrical guide section, and the bottom of the spinneret is equipped with a central sealing plate. Each side of the central sealing plate has an annular slit. The central sealing plate is connected to the wall of the spinneret via two ear-shaped connectors, the width of which is much smaller than the circumference of the annular slits. The lower end of the boss of the third distribution plate extends into the guide section above the spinneret, leaving an annular gap between them for the melt to flow through. This design ensures that the pre-arranged melt flowing from the lower end face of the boss can be smoothly guided into the spinneret, avoiding turbulence or interface disturbance at the inlet. After being extruded through the spinneret, the first and second melts ultimately form a hollow, orange-petal-shaped fiber.

[0029] Compared with the prior art, the present invention has the following significant advantages:

[0030] 1. Significantly Improved Fiber Cross-Section Quality: The core of this invention lies in the "pre-arranged boss structure," which forcibly fixes the spatial position of the melt before it enters the spinneret. This fundamentally solves the problem of random and unstable interface state of the melt at the spinneret inlet in traditional designs, thereby enabling the stable and continuous spinning of composite fibers with regular orange-petal shape, uniform size, and clear interface, providing a fundamental guarantee for obtaining uniformly thick ultrafine fibers in the future.

[0031] 2. Superior Stability and Uniformity of Component Operation: Through a three-stage distribution and guidance system of "first distribution plate (circumferential distribution) → second distribution plate (radial diversion) → third distribution plate (convergence and preforming)," the melt flow path is logically clear and each component performs its specific function. Compared to complex multi-layered staggered flow channels, this novel structure reduces flow resistance and the risk of stagnation, ensuring the consistency of melt pressure and flow rate reaching each boss structure, thereby significantly improving the uniformity of filament output from the entire spinneret and the stability of the production process.

[0032] 3. Simplified equipment structure and convenient maintenance: The most precise "pre-forming" function is concentrated on the boss of the third distribution plate, while other distribution plates mainly undertake the task of guiding the flow. This modular design makes the core functional components relatively simple in structure, easy to process and inspect. At the same time, when it is necessary to adjust the number or shape of the segments, theoretically it can be achieved by replacing or modifying the third distribution plate (especially the boss part), which improves the versatility and flexibility of the equipment and reduces maintenance costs. Attached Figure Description

[0033] To make the above-mentioned objectives, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are simplified or schematic in style and are only used to assist in illustrating the concept of this utility model; they should not be construed as limiting the scope of protection of this utility model. The same reference numerals in the drawings represent the same or similar components.

[0034] Figure 1 This is a three-dimensional structural diagram of an embodiment of the orange-petal-shaped composite fiber spinneret assembly of this utility model.

[0035] Figure 2 for Figure 1 Exploded view.

[0036] Figure 3 for Figure 1 A schematic diagram of the front structure of the second distribution plate.

[0037] Figure 4 for Figure 1 A schematic diagram of the front structure of the third distribution plate.

[0038] Figure 5 for Figure 1 A schematic diagram of the reverse structure of the third distribution plate.

[0039] Figure 6 for Figure 5 A magnified view of part B in the middle section.

[0040] Figure 7 for Figure 1 Cross-sectional view of the spinneret.

[0041] Figure 8 for Figure 7 A magnified view of the spinneret orifice in the B direction.

[0042] Figure 9 for Figure 1 A cross-sectional view.

[0043] Figure 10 This is a schematic diagram of the cross-sectional structure of the orange-petal-shaped composite fiber prepared using the spinneret assembly of this invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. First distribution plate; 11. First annular flow channel; 12. Second annular flow channel; 13. First through hole; 14. Second through hole; 2. Second distribution plate; 21. First guide groove; 22. Second guide groove; 23. Third through hole; 24. Fourth through hole; 3. Third distribution plate; 31. First annular material trough; 32. Second annular material trough; 33. Boss; 331. Discharge hole; 332. Material passage groove; 4. Spinneret; 41. Spinneret hole; 410. Central sealing plate; 411. Annular slit; 412. Ear connector; 5. Center bolt; 6. Positioning pin; A. First melt; B. Second melt. Detailed Implementation

[0046] The technical solution of this utility model will be described in detail and completely below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will understand that these descriptions are exemplary and not intended to limit the scope of protection of this utility model.

[0047] This utility model provides a spinneret assembly and its preparation method for efficiently and stably producing orange-petal-shaped composite fibers. Figure 1 and Figure 2 As shown, the spinneret assembly is generally circular and mainly consists of four precision-machined plates aligned from top to bottom by positioning pins 6 and fastened together by a central bolt 5. These four plates are, in order, the first distribution plate 1, the second distribution plate 2, the third distribution plate 3, and the spinneret 4. The melt flow follows a top-to-bottom path, and each plate layer undertakes a specific fluid distribution and shaping function.

[0048] The first distribution plate 1, serving as the initial distribution hub for the melt, is characterized by two concentric annular channels with different diameters on its upper surface. The inner channel with a smaller diameter is the first annular channel 11, and the outer channel with a larger diameter is the second annular channel 12. These two channels are physically isolated and do not communicate with each other. The first melt A (e.g., polyester PET) is introduced into the first annular channel 11 through a feeding device (not shown) connected to it from above, while the second melt B (e.g., polyamide 6 PA6) is independently introduced into the second annular channel 12. This concentric annular channel design cleverly utilizes the melt's own pressure and fluidity to achieve a primary uniform distribution of the two components in the circumferential direction, laying the foundation for pressure balance in subsequent fine distribution. As an alternative implementation, the number of annular channels can be more than two, for example, three or more, to accommodate the composite spinning requirements of three or more components. In this case, the channels still need to remain isolated from each other. Multiple first through holes 13 and second through holes 14 penetrating the first distribution plate 1 are respectively provided at intervals within the first annular channel 11 and the second annular channel 12.

[0049] The second distribution plate 2 receives the circumferentially distributed melt from the first distribution plate 1 and converts it into multiple independent streams pointing to specific radial positions. For example... Figure 3 As shown in the top view, several radially extending strip-shaped guide channels are machined on the upper surface of the plate. These guide channels are of two specifications: the longer ones, extending close to the outer edge of the plate, are the first guide channels 21, whose positions correspond one-to-one with the first through holes 13 in the first annular flow channel 11; the shorter ones, located in the middle of the plate, are the second guide channels 22, whose positions correspond one-to-one with the second through holes 14 in the second annular flow channel 12. The first guide channels 21 and the second guide channels 22 are arranged alternately and at intervals in the circumferential direction. On the lower surface of the second distribution plate 2, corresponding to the positions of each first guide channel 21 and second guide channel 22, multiple third through holes 23 and fourth through holes 24 are machined to communicate with them. When the melt falls from the annular flow channel of the first distribution plate 1 into the corresponding guide channel, it will diffuse and fill along the strip-shaped channel, and then flow vertically downward from each through hole under pressure. This design enables the transformation of fluid form and precise spatial positioning from "surface" (annular flow channel) to "line" (strip groove) and then to "point" (through hole). In a preferred embodiment, to compensate for differences in fluid resistance, the diameter of the third through hole 23 located on different radial layers can be designed to be different. For example, the diameter of the through holes in the outermost and innermost rings can be slightly smaller than the diameter of the through holes in the middle rings to ensure the uniformity of all outlet flow rates.

[0050] The third distribution plate 3 is the innovative core of the entire assembly, undertaking the crucial mission of performing the final "pre-arrangement" of the two melts. For example... Figure 4 and Figure 5As shown, its upper surface, corresponding to the outlet positions of each through hole in the second distribution plate 2, is machined with mutually spaced annular collecting grooves. Specifically, corresponding to the positions of all third through holes 23, four rings of first annular material grooves 31 are provided; corresponding to the positions of all fourth through holes 24, three rings of second annular material grooves 32 are provided. In this embodiment, the second annular material grooves 32 are located exactly between two rings of first annular material grooves 31, forming an "ABA" sandwich radial layout. This layout is beneficial to the mechanical balance of the final fiber cross-section structure.

[0051] The essence of this utility model is concentrated on the lower surface of the third distribution plate 3. For example... Figure 5 and Figure 6 Clearly shown, on its lower surface, corresponding to each spinning point (i.e., the location where a spinneret will eventually form), there is a downward-protruding cylindrical boss 33. This boss 33 is a "forming mold" before melt bonding. Figure 6 As shown in the enlarged view, multiple (e.g., eight) vertically penetrating discharge holes 331 are machined on the lower end face of the boss 33. These discharge holes 331 are small-diameter through holes, and their upper ends communicate with the second annular groove 32 on the upper surface. Simultaneously, material passage grooves 332, corresponding in number and position to the discharge holes 331, are machined on the sidewall of the boss 33. These material passage grooves 332 are designed as elongated slots that cut into the upper part of the boss's sidewall, extend downwards, and penetrate to the lower end face of the boss. The upper ends of these slots communicate with the first annular groove 31. Crucially, the discharge holes 331 and material passage grooves 332 are arranged in an alternating circular pattern on the lower end face of the boss 33. They can alternate strictly one-to-one, forming a highly regular pattern. As an alternative implementation, the arrangement is not limited to a one-to-one circular arrangement. It can also be a "two-hole-one-groove" or "one-hole-two-groove" as a repeating unit, or arranged in a non-circular symmetrical pattern (such as a rectangular distribution). As long as the core feature of "alternating arrangement" is met, the separation and recombination of the melt can be achieved. The width of the feed groove 332 is preferably 0.3-0.5 mm, and the depth is 0.4-0.6 mm; the diameter of the discharge hole 331 is preferably 0.2-0.4 mm.

[0052] The spinneret 4 is located at the bottom layer, and the final shaped spinneret holes 41 are machined on it. For example... Figures 7 to 9As shown, the upper part of the spinneret 41 is typically designed as a conical or cylindrical guide section. A central sealing plate 410 is located at the bottom of the spinneret 41, with annular slits 411 formed on both sides of the central sealing plate 410. The central sealing plate 410 is connected to the wall of the spinneret 41 via two ear connectors 412. The annular slits 411 are formed on both sides of the central sealing plate 410 via the two ear connectors 412, and the width of the ear connectors 412 is much smaller than the circumference of the annular slits 411. The ear connectors 412 are used to support the central sealing plate 410. A key assembly relationship is that the lower end of the boss 33 of the third distribution plate 3 needs to precisely extend into the guide section of the upper part of the spinneret 41, leaving an annular gap between them for the melt to flow through. This design ensures that the pre-arranged melt flowing out from the lower end face of the boss 33 can be smoothly guided into the spinneret 41, avoiding turbulence or interface disturbance at the inlet. After the first melt A and the second melt B are extruded through the annular slit 411 of the spinneret 41, they ultimately become a hollow, orange-petal-shaped fiber. Due to the extremely narrow control of the ear connector 412, approximately 0.06mm-0.12mm wide, the polymer melt molecular chains are highly stretched and oriented in the thermal flow field, storing a large amount of elastic deformation energy. The moment the two melts flow out of the annular slit 411, the constraint suddenly disappears, and the pressure drops to zero. The previously stretched molecular chains, like a released spring, rapidly retract and relax, resulting in a significant "exit expansion" effect in the melt. The expansion direction is exactly opposite to each other. The two highly activated, temperature-uniform melts, which are in a viscous flow state, instantly come into contact and are squeezed together. Therefore, when the melt flows down, it will not be cut into two half-ring filaments, but will form a complete hollow filament.

[0053] Please see Figure 2 The connection method of the spinneret assembly is as follows: each distribution plate and the spinneret 4 have positioning pin holes on both sides of the edge. After the two positioning pins 6 are passed through each plate in sequence to achieve positioning, they are fixed by bolts 5 arranged in the center. The center of the first distribution plate 1 is designed with a threaded blind hole that matches the bolt 5. After the bolt 5 is passed through the spinneret 4, the third distribution plate 3, and the second distribution plate 2 in sequence, it is screwed into the threaded blind hole in the center of the first distribution plate 1 for fixation.

[0054] Combining the working principle and manufacturing method of the component Figure 9The cross-sectional view is illustrated below: First, PET and PA6 chips are melted separately in a screw extruder, and after metering, a first melt A (marked in blue in the figure) and a second melt B (marked in red in the figure) are obtained. The two melts are independently conveyed to the top of the assembled spinneret assembly. The first melt A enters the first annular flow channel 11, is distributed by the first guide groove 21, and flows into the first annular feed trough 31 of the third distribution plate 3 through multiple third through holes 23, finally converging at each boss 33 and flowing out from the feed trough 332. At the same time, the second melt B follows the same logical path (second annular flow channel 12 → second guide groove 22 → fourth through hole 24 → second annular feed trough 32), finally reaching each boss 33, and is extruded vertically downward from the discharge hole 331 in the form of multiple fine streams. Since the feed trough 332 is laterally open, the outflow direction of the first melt A has a certain radial component.

[0055] Within the narrow space between the lower end face of the boss 33 and the inlet of the spinneret 41, the vertically downward flow of the second melt B from the discharge hole 331 meets the slightly inclined flow of the first melt A from the feed trough 332. Because they are physically forced to be spaced apart circumferentially, large-scale mixing does not occur here; instead, an initial composite interface with alternating spatial intervals is immediately formed. Subsequently, this group of melt streams, already possessing a preliminary pattern, is forced together into the lower spinneret 41 under pressure. Under the shear flow and stretching action of the spinneret 41, the melt interface is further refined and solidified. Finally, after being extruded from the spinneret 41 and cooled and solidified by side blowing, a cross-sectional structure is formed as shown in the image. Figure 10 The image shows an orange petal-shaped composite fiber. In the cross-section of this fiber, the PET component (A) and PA6 component (B) are arranged clearly and regularly like flower petals, with distinct interfaces.

[0056] To obtain the final commercial microfiber product, the aforementioned nascent fibers require further processing. The resulting orange-petal-shaped composite fiber filaments are subjected to high-pressure hydroentangling using a mechanical hydroentangling machine, or woven into fabric and then treated in an alkaline solution (because PET is not resistant to strong alkalis while PA6 is). During this process, the interface between the two components is disrupted under mechanical or chemical action, causing the entire composite fiber to split into a significantly increased number of single-component (PET or PA6) microfiber filaments, forming a fluffy and soft fiber web. This fiber-opening step is a crucial step in realizing the value of this technical solution.

[0057] Technical Effect Verification: By adopting the spinneret assembly and method of this utility model, the following verifiable positive effects can be achieved: 1) High fiber output stability: Due to the pre-arrangement effect of the boss structure, random co-flow of melt at the spinneret inlet is completely avoided, and the breakage rate during spinning is significantly reduced. 2) Excellent fiber cross-sectional uniformity: Under a microscope, the fiber produced by different spinnerets shows that the consistency of the number, shape, and size of the segments exceeds 95%, which is far superior to the traditional distribution method. 3) Improved fiber opening efficiency and quality: The regular and clear interface makes subsequent hydroentangling or alkali reduction fiber opening easier and more thorough, improves the uniformity of the thickness of the obtained ultrafine fiber bundles, reduces the number of residual unsplit "hard points," and substantially improves the softness and feel of the final product.

[0058] The above description is merely a preferred embodiment of this utility model, illustrating a specific case of using PET as the first component and PA6 as the second component to form an 8-petal structure. Those skilled in the art can make various modifications based on the concept of this utility model. For example, the materials of the first and second components can be interchanged, or other polymer combinations (such as PET / PP, PA / PE, etc.) can be used; the number of petals can be flexibly adjusted to 4, 6, 10, or 16 petals by increasing or decreasing the number of small through holes and grooves on the protrusions; the number of rings in the annular collecting groove on the third distribution plate can also be increased according to product design requirements. Any technical solution that adopts the same or similar fluid pre-arrangement logic as this design, forcibly forming spaced parallel melt flows through the upstream structure, and then performing composite spinning, should fall within the protection scope of the claims of this utility model.

Claims

1. A spinneret assembly for orange-petal-shaped composite fibers, characterized in that, It includes a first distribution plate (1), a second distribution plate (2), a third distribution plate (3), and a spinneret (4) that are stacked and fluidly connected from top to bottom. The first distribution plate (1) is provided with a first annular flow channel (11) and a second annular flow channel (12) that are isolated from each other, which are used to receive and distribute the first melt (A) and the second melt (B) respectively; the first annular flow channel (11) and the second annular flow channel (12) are respectively provided with a plurality of first through holes (13) and second through holes (14) that penetrate the first distribution plate (1). The upper surface of the second distribution plate (2) is provided with a plurality of first guide grooves (21) and second guide grooves (22) corresponding to the positions of the first through hole (13) and the second through hole (14), and its lower surface is provided with a plurality of third through holes (23) and fourth through holes (24) respectively communicating with the first guide grooves (21) and the second guide grooves (22) and guiding the melt downward. The upper surface of the third distribution plate (3) is provided with at least one ring of first annular material groove (31) and at least one ring of second annular material groove (32) spaced apart from each other, corresponding to the positions of the third through hole (23) and the fourth through hole (24); the lower surface of the third distribution plate (3) is provided with a downward protruding boss (33), the boss (33) is provided with a plurality of discharge holes (331) communicating with the second annular material groove (32) and a plurality of material passage grooves (332) communicating with the first annular material groove (31), the discharge holes (331) and the material passage grooves (332) are arranged alternately on the lower end face of the boss (33); The spinneret (4) is provided with a spinneret hole (41), and the lower end of the boss (33) extends into the upper part of the spinneret hole (41), so that the second melt (B) and the first melt (A) from the discharge hole (331) and the feed groove (332) merge and are extruded in the spinneret hole (41) in a spaced-apart parallel form.

2. The spinneret assembly for the orange-petal-shaped composite fiber according to claim 1, characterized in that, The first annular flow channel (11) and the second annular flow channel (12) on the first distribution plate (1) are concentric annular grooves, and the diameter of the second annular flow channel (12) is larger than the diameter of the first annular flow channel (11).

3. The spinneret assembly for the orange-petal-shaped composite fiber according to claim 1, characterized in that, The first guide groove (21) and the second guide groove (22) on the second distribution plate (2) are strip-shaped grooves extending radially, and the length of the first guide groove (21) is greater than the length of the second guide groove (22).

4. The spinneret assembly for the orange-petal-shaped composite fiber according to claim 1, characterized in that, The third distribution plate (3) is provided with N+1 rings of first annular material troughs (31) and N rings of second annular material troughs (32). The second annular material troughs (32) are located between two rings of first annular material troughs (31), where N≥1. All annular material troughs are concentrically distributed radially along the third distribution plate.

5. The spinneret assembly for the orange-petal-shaped composite fiber according to claim 1, characterized in that, The feed groove (332) is a groove formed on the side of the boss (33) and extending to its lower end face, and the discharge hole (331) is a vertical micro-hole that penetrates the boss (33).

6. The spinneret assembly of the orange-petal-shaped composite fiber according to any one of claims 1 to 5, characterized in that, The number of discharge holes (331) and material passages (332) are both 4-12, and they are evenly and alternately arranged.

7. The spinneret assembly of the orange-petal-shaped composite fiber according to any one of claims 1 to 5, characterized in that, The upper part of the spinneret is designed as a conical or cylindrical guide section, and a central sealing plate is provided at the bottom of the spinneret. An annular slit is formed on each side of the central sealing plate. The central sealing plate is connected to the wall of the spinneret through two ear connectors. The width of the ear connectors is much smaller than the circumference of the annular slits. The lower end of the boss of the third distribution plate extends into the guide section of the upper part of the spinneret, and an annular gap is left between the two for the melt to flow through.

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